drivers/media/video/mt9t031.c

   1 /*
   2  * Driver for MT9T031 CMOS Image Sensor from Micron
   3  *
   4  * Copyright (C) 2008, Guennadi Liakhovetski, DENX Software Engineering <lg@denx.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/videodev2.h>
  12 #include <linux/slab.h>
  13 #include <linux/i2c.h>
  14 #include <linux/log2.h>
  15
  16 #include <media/v4l2-subdev.h>
  17 #include <media/v4l2-chip-ident.h>
  18 #include <media/soc_camera.h>
  19
  20 /* mt9t031 i2c address 0x5d
  21  * The platform has to define i2c_board_info and link to it from
  22  * struct soc_camera_link */
  23
  24 /* mt9t031 selected register addresses */
  25 #define MT9T031_CHIP_VERSION            0x00
  26 #define MT9T031_ROW_START               0x01
  27 #define MT9T031_COLUMN_START            0x02
  28 #define MT9T031_WINDOW_HEIGHT           0x03
  29 #define MT9T031_WINDOW_WIDTH            0x04
  30 #define MT9T031_HORIZONTAL_BLANKING     0x05
  31 #define MT9T031_VERTICAL_BLANKING       0x06
  32 #define MT9T031_OUTPUT_CONTROL          0x07
  33 #define MT9T031_SHUTTER_WIDTH_UPPER     0x08
  34 #define MT9T031_SHUTTER_WIDTH           0x09
  35 #define MT9T031_PIXEL_CLOCK_CONTROL     0x0a
  36 #define MT9T031_FRAME_RESTART           0x0b
  37 #define MT9T031_SHUTTER_DELAY           0x0c
  38 #define MT9T031_RESET                   0x0d
  39 #define MT9T031_READ_MODE_1             0x1e
  40 #define MT9T031_READ_MODE_2             0x20
  41 #define MT9T031_READ_MODE_3             0x21
  42 #define MT9T031_ROW_ADDRESS_MODE        0x22
  43 #define MT9T031_COLUMN_ADDRESS_MODE     0x23
  44 #define MT9T031_GLOBAL_GAIN             0x35
  45 #define MT9T031_CHIP_ENABLE             0xF8
  46
  47 #define MT9T031_MAX_HEIGHT              1536
  48 #define MT9T031_MAX_WIDTH               2048
  49 #define MT9T031_MIN_HEIGHT              2
  50 #define MT9T031_MIN_WIDTH               18
  51 #define MT9T031_HORIZONTAL_BLANK        142
  52 #define MT9T031_VERTICAL_BLANK          25
  53 #define MT9T031_COLUMN_SKIP             32
  54 #define MT9T031_ROW_SKIP                20
  55
  56 #define MT9T031_BUS_PARAM       (SOCAM_PCLK_SAMPLE_RISING |     \
  57         SOCAM_PCLK_SAMPLE_FALLING | SOCAM_HSYNC_ACTIVE_HIGH |   \
  58         SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_HIGH |      \
  59         SOCAM_MASTER | SOCAM_DATAWIDTH_10)
  60
  61 static const struct soc_camera_data_format mt9t031_colour_formats[] = {
  62         {
  63                 .name           = "Bayer (sRGB) 10 bit",
  64                 .depth          = 10,
  65                 .fourcc         = V4L2_PIX_FMT_SGRBG10,
  66                 .colorspace     = V4L2_COLORSPACE_SRGB,
  67         }
  68 };
  69
  70 struct mt9t031 {
  71         struct v4l2_subdev subdev;
  72         struct v4l2_rect rect;  /* Sensor window */
  73         int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
  74         u16 xskip;
  75         u16 yskip;
  76         unsigned int gain;
  77         unsigned short y_skip_top;      /* Lines to skip at the top */
  78         unsigned int exposure;
  79         unsigned char autoexposure;
  80 };
  81
  82 static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
  83 {
  84         return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
  85 }
  86
  87 static int reg_read(struct i2c_client *client, const u8 reg)
  88 {
  89         s32 data = i2c_smbus_read_word_data(client, reg);
  90         return data < 0 ? data : swab16(data);
  91 }
  92
  93 static int reg_write(struct i2c_client *client, const u8 reg,
  94                      const u16 data)
  95 {
  96         return i2c_smbus_write_word_data(client, reg, swab16(data));
  97 }
  98
  99 static int reg_set(struct i2c_client *client, const u8 reg,
 100                    const u16 data)
 101 {
 102         int ret;
 103
 104         ret = reg_read(client, reg);
 105         if (ret < 0)
 106                 return ret;
 107         return reg_write(client, reg, ret | data);
 108 }
 109
 110 static int reg_clear(struct i2c_client *client, const u8 reg,
 111                      const u16 data)
 112 {
 113         int ret;
 114
 115         ret = reg_read(client, reg);
 116         if (ret < 0)
 117                 return ret;
 118         return reg_write(client, reg, ret & ~data);
 119 }
 120
 121 static int set_shutter(struct i2c_client *client, const u32 data)
 122 {
 123         int ret;
 124
 125         ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
 126
 127         if (ret >= 0)
 128                 ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
 129
 130         return ret;
 131 }
 132
 133 static int get_shutter(struct i2c_client *client, u32 *data)
 134 {
 135         int ret;
 136
 137         ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
 138         *data = ret << 16;
 139
 140         if (ret >= 0)
 141                 ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
 142         *data |= ret & 0xffff;
 143
 144         return ret < 0 ? ret : 0;
 145 }
 146
 147 static int mt9t031_idle(struct i2c_client *client)
 148 {
 149         int ret;
 150
 151         /* Disable chip output, synchronous option update */
 152         ret = reg_write(client, MT9T031_RESET, 1);
 153         if (ret >= 0)
 154                 ret = reg_write(client, MT9T031_RESET, 0);
 155         if (ret >= 0)
 156                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 157
 158         return ret >= 0 ? 0 : -EIO;
 159 }
 160
 161 static int mt9t031_disable(struct i2c_client *client)
 162 {
 163         /* Disable the chip */
 164         reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 165
 166         return 0;
 167 }
 168
 169 static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
 170 {
 171         struct i2c_client *client = sd->priv;
 172         int ret;
 173
 174         if (enable)
 175                 /* Switch to master "normal" mode */
 176                 ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
 177         else
 178                 /* Stop sensor readout */
 179                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
 180
 181         if (ret < 0)
 182                 return -EIO;
 183
 184         return 0;
 185 }
 186
 187 static int mt9t031_set_bus_param(struct soc_camera_device *icd,
 188                                  unsigned long flags)
 189 {
 190         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 191
 192         /* The caller should have queried our parameters, check anyway */
 193         if (flags & ~MT9T031_BUS_PARAM)
 194                 return -EINVAL;
 195
 196         if (flags & SOCAM_PCLK_SAMPLE_FALLING)
 197                 reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 198         else
 199                 reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
 200
 201         return 0;
 202 }
 203
 204 static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
 205 {
 206         struct soc_camera_link *icl = to_soc_camera_link(icd);
 207
 208         return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
 209 }
 210
 211 /* target must be _even_ */
 212 static u16 mt9t031_skip(s32 *source, s32 target, s32 max)
 213 {
 214         unsigned int skip;
 215
 216         if (*source < target + target / 2) {
 217                 *source = target;
 218                 return 1;
 219         }
 220
 221         skip = min(max, *source + target / 2) / target;
 222         if (skip > 8)
 223                 skip = 8;
 224         *source = target * skip;
 225
 226         return skip;
 227 }
 228
 229 /* rect is the sensor rectangle, the caller guarantees parameter validity */
 230 static int mt9t031_set_params(struct soc_camera_device *icd,
 231                               struct v4l2_rect *rect, u16 xskip, u16 yskip)
 232 {
 233         struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
 234         struct mt9t031 *mt9t031 = to_mt9t031(client);
 235         int ret;
 236         u16 xbin, ybin;
 237         const u16 hblank = MT9T031_HORIZONTAL_BLANK,
 238                 vblank = MT9T031_VERTICAL_BLANK;
 239
 240         xbin = min(xskip, (u16)3);
 241         ybin = min(yskip, (u16)3);
 242
 243         /*
 244          * Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper.
 245          * There is always a valid suitably aligned value. The worst case is
 246          * xbin = 3, width = 2048. Then we will start at 36, the last read out
 247          * pixel will be 2083, which is < 2085 - first black pixel.
 248          *
 249          * MT9T031 datasheet imposes window left border alignment, depending on
 250          * the selected xskip. Failing to conform to this requirement produces
 251          * dark horizontal stripes in the image. However, even obeying to this
 252          * requirement doesn't eliminate the stripes in all configurations. They
 253          * appear "locally reproducibly," but can differ between tests under
 254          * different lighting conditions.
 255          */
 256         switch (xbin) {
 257         case 1:
 258                 rect->left &= ~1;
 259                 break;
 260         case 2:
 261                 rect->left &= ~3;
 262                 break;
 263         case 3:
 264                 rect->left = rect->left > roundup(MT9T031_COLUMN_SKIP, 6) ?
 265                         (rect->left / 6) * 6 : roundup(MT9T031_COLUMN_SKIP, 6);
 266         }
 267
 268         rect->top &= ~1;
 269
 270         dev_dbg(&client->dev, "skip %u:%u, rect %ux%u@%u:%u\n",
 271                 xskip, yskip, rect->width, rect->height, rect->left, rect->top);
 272
 273         /* Disable register update, reconfigure atomically */
 274         ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
 275         if (ret < 0)
 276                 return ret;
 277
 278         /* Blanking and start values - default... */
 279         ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
 280         if (ret >= 0)
 281                 ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
 282
 283         if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
 284                 /* Binning, skipping */
 285                 if (ret >= 0)
 286                         ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
 287                                         ((xbin - 1) << 4) | (xskip - 1));
 288                 if (ret >= 0)
 289                         ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
 290                                         ((ybin - 1) << 4) | (yskip - 1));
 291         }
 292         dev_dbg(&client->dev, "new physical left %u, top %u\n",
 293                 rect->left, rect->top);
 294
 295         /* The caller provides a supported format, as guaranteed by
 296          * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap() */
 297         if (ret >= 0)
 298                 ret = reg_write(client, MT9T031_COLUMN_START, rect->left);
 299         if (ret >= 0)
 300                 ret = reg_write(client, MT9T031_ROW_START, rect->top);
 301         if (ret >= 0)
 302                 ret = reg_write(client, MT9T031_WINDOW_WIDTH, rect->width - 1);
 303         if (ret >= 0)
 304                 ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
 305                                 rect->height + mt9t031->y_skip_top - 1);
 306         if (ret >= 0 && mt9t031->autoexposure) {
 307                 unsigned int total_h = rect->height + mt9t031->y_skip_top + vblank;
 308                 ret = set_shutter(client, total_h);
 309                 if (ret >= 0) {
 310                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 311                         const struct v4l2_queryctrl *qctrl =
 312                                 soc_camera_find_qctrl(icd->ops,
 313                                                       V4L2_CID_EXPOSURE);
 314                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 315                                  (qctrl->maximum - qctrl->minimum)) /
 316                                 shutter_max + qctrl->minimum;
 317                 }
 318         }
 319
 320         /* Re-enable register update, commit all changes */
 321         if (ret >= 0)
 322                 ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
 323
 324         if (ret >= 0) {
 325                 mt9t031->rect = *rect;
 326                 mt9t031->xskip = xskip;
 327                 mt9t031->yskip = yskip;
 328         }
 329
 330         return ret < 0 ? ret : 0;
 331 }
 332
 333 static int mt9t031_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 334 {
 335         struct v4l2_rect rect = a->c;
 336         struct i2c_client *client = sd->priv;
 337         struct mt9t031 *mt9t031 = to_mt9t031(client);
 338         struct soc_camera_device *icd = client->dev.platform_data;
 339
 340         rect.width = ALIGN(rect.width, 2);
 341         rect.height = ALIGN(rect.height, 2);
 342
 343         soc_camera_limit_side(&rect.left, &rect.width,
 344                      MT9T031_COLUMN_SKIP, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH);
 345
 346         soc_camera_limit_side(&rect.top, &rect.height,
 347                      MT9T031_ROW_SKIP, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT);
 348
 349         return mt9t031_set_params(icd, &rect, mt9t031->xskip, mt9t031->yskip);
 350 }
 351
 352 static int mt9t031_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 353 {
 354         struct i2c_client *client = sd->priv;
 355         struct mt9t031 *mt9t031 = to_mt9t031(client);
 356
 357         a->c    = mt9t031->rect;
 358         a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 359
 360         return 0;
 361 }
 362
 363 static int mt9t031_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
 364 {
 365         a->bounds.left                  = MT9T031_COLUMN_SKIP;
 366         a->bounds.top                   = MT9T031_ROW_SKIP;
 367         a->bounds.width                 = MT9T031_MAX_WIDTH;
 368         a->bounds.height                = MT9T031_MAX_HEIGHT;
 369         a->defrect                      = a->bounds;
 370         a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 371         a->pixelaspect.numerator        = 1;
 372         a->pixelaspect.denominator      = 1;
 373
 374         return 0;
 375 }
 376
 377 static int mt9t031_g_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 378 {
 379         struct i2c_client *client = sd->priv;
 380         struct mt9t031 *mt9t031 = to_mt9t031(client);
 381         struct v4l2_pix_format *pix = &f->fmt.pix;
 382
 383         pix->width              = mt9t031->rect.width / mt9t031->xskip;
 384         pix->height             = mt9t031->rect.height / mt9t031->yskip;
 385         pix->pixelformat        = V4L2_PIX_FMT_SGRBG10;
 386         pix->field              = V4L2_FIELD_NONE;
 387         pix->colorspace         = V4L2_COLORSPACE_SRGB;
 388
 389         return 0;
 390 }
 391
 392 static int mt9t031_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 393 {
 394         struct i2c_client *client = sd->priv;
 395         struct mt9t031 *mt9t031 = to_mt9t031(client);
 396         struct soc_camera_device *icd = client->dev.platform_data;
 397         struct v4l2_pix_format *pix = &f->fmt.pix;
 398         u16 xskip, yskip;
 399         struct v4l2_rect rect = mt9t031->rect;
 400
 401         /*
 402          * try_fmt has put width and height within limits.
 403          * S_FMT: use binning and skipping for scaling
 404          */
 405         xskip = mt9t031_skip(&rect.width, pix->width, MT9T031_MAX_WIDTH);
 406         yskip = mt9t031_skip(&rect.height, pix->height, MT9T031_MAX_HEIGHT);
 407
 408         /* mt9t031_set_params() doesn't change width and height */
 409         return mt9t031_set_params(icd, &rect, xskip, yskip);
 410 }
 411
 412 /*
 413  * If a user window larger than sensor window is requested, we'll increase the
 414  * sensor window.
 415  */
 416 static int mt9t031_try_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
 417 {
 418         struct v4l2_pix_format *pix = &f->fmt.pix;
 419
 420         v4l_bound_align_image(
 421                 &pix->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
 422                 &pix->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
 423
 424         return 0;
 425 }
 426
 427 static int mt9t031_g_chip_ident(struct v4l2_subdev *sd,
 428                                 struct v4l2_dbg_chip_ident *id)
 429 {
 430         struct i2c_client *client = sd->priv;
 431         struct mt9t031 *mt9t031 = to_mt9t031(client);
 432
 433         if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
 434                 return -EINVAL;
 435
 436         if (id->match.addr != client->addr)
 437                 return -ENODEV;
 438
 439         id->ident       = mt9t031->model;
 440         id->revision    = 0;
 441
 442         return 0;
 443 }
 444
 445 #ifdef CONFIG_VIDEO_ADV_DEBUG
 446 static int mt9t031_g_register(struct v4l2_subdev *sd,
 447                               struct v4l2_dbg_register *reg)
 448 {
 449         struct i2c_client *client = sd->priv;
 450
 451         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 452                 return -EINVAL;
 453
 454         if (reg->match.addr != client->addr)
 455                 return -ENODEV;
 456
 457         reg->val = reg_read(client, reg->reg);
 458
 459         if (reg->val > 0xffff)
 460                 return -EIO;
 461
 462         return 0;
 463 }
 464
 465 static int mt9t031_s_register(struct v4l2_subdev *sd,
 466                               struct v4l2_dbg_register *reg)
 467 {
 468         struct i2c_client *client = sd->priv;
 469
 470         if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
 471                 return -EINVAL;
 472
 473         if (reg->match.addr != client->addr)
 474                 return -ENODEV;
 475
 476         if (reg_write(client, reg->reg, reg->val) < 0)
 477                 return -EIO;
 478
 479         return 0;
 480 }
 481 #endif
 482
 483 static const struct v4l2_queryctrl mt9t031_controls[] = {
 484         {
 485                 .id             = V4L2_CID_VFLIP,
 486                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 487                 .name           = "Flip Vertically",
 488                 .minimum        = 0,
 489                 .maximum        = 1,
 490                 .step           = 1,
 491                 .default_value  = 0,
 492         }, {
 493                 .id             = V4L2_CID_HFLIP,
 494                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 495                 .name           = "Flip Horizontally",
 496                 .minimum        = 0,
 497                 .maximum        = 1,
 498                 .step           = 1,
 499                 .default_value  = 0,
 500         }, {
 501                 .id             = V4L2_CID_GAIN,
 502                 .type           = V4L2_CTRL_TYPE_INTEGER,
 503                 .name           = "Gain",
 504                 .minimum        = 0,
 505                 .maximum        = 127,
 506                 .step           = 1,
 507                 .default_value  = 64,
 508                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 509         }, {
 510                 .id             = V4L2_CID_EXPOSURE,
 511                 .type           = V4L2_CTRL_TYPE_INTEGER,
 512                 .name           = "Exposure",
 513                 .minimum        = 1,
 514                 .maximum        = 255,
 515                 .step           = 1,
 516                 .default_value  = 255,
 517                 .flags          = V4L2_CTRL_FLAG_SLIDER,
 518         }, {
 519                 .id             = V4L2_CID_EXPOSURE_AUTO,
 520                 .type           = V4L2_CTRL_TYPE_BOOLEAN,
 521                 .name           = "Automatic Exposure",
 522                 .minimum        = 0,
 523                 .maximum        = 1,
 524                 .step           = 1,
 525                 .default_value  = 1,
 526         }
 527 };
 528
 529 static struct soc_camera_ops mt9t031_ops = {
 530         .set_bus_param          = mt9t031_set_bus_param,
 531         .query_bus_param        = mt9t031_query_bus_param,
 532         .controls               = mt9t031_controls,
 533         .num_controls           = ARRAY_SIZE(mt9t031_controls),
 534 };
 535
 536 static int mt9t031_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 537 {
 538         struct i2c_client *client = sd->priv;
 539         struct mt9t031 *mt9t031 = to_mt9t031(client);
 540         int data;
 541
 542         switch (ctrl->id) {
 543         case V4L2_CID_VFLIP:
 544                 data = reg_read(client, MT9T031_READ_MODE_2);
 545                 if (data < 0)
 546                         return -EIO;
 547                 ctrl->value = !!(data & 0x8000);
 548                 break;
 549         case V4L2_CID_HFLIP:
 550                 data = reg_read(client, MT9T031_READ_MODE_2);
 551                 if (data < 0)
 552                         return -EIO;
 553                 ctrl->value = !!(data & 0x4000);
 554                 break;
 555         case V4L2_CID_EXPOSURE_AUTO:
 556                 ctrl->value = mt9t031->autoexposure;
 557                 break;
 558         case V4L2_CID_GAIN:
 559                 ctrl->value = mt9t031->gain;
 560                 break;
 561         case V4L2_CID_EXPOSURE:
 562                 ctrl->value = mt9t031->exposure;
 563                 break;
 564         }
 565         return 0;
 566 }
 567
 568 static int mt9t031_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 569 {
 570         struct i2c_client *client = sd->priv;
 571         struct mt9t031 *mt9t031 = to_mt9t031(client);
 572         struct soc_camera_device *icd = client->dev.platform_data;
 573         const struct v4l2_queryctrl *qctrl;
 574         int data;
 575
 576         qctrl = soc_camera_find_qctrl(&mt9t031_ops, ctrl->id);
 577
 578         if (!qctrl)
 579                 return -EINVAL;
 580
 581         switch (ctrl->id) {
 582         case V4L2_CID_VFLIP:
 583                 if (ctrl->value)
 584                         data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
 585                 else
 586                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
 587                 if (data < 0)
 588                         return -EIO;
 589                 break;
 590         case V4L2_CID_HFLIP:
 591                 if (ctrl->value)
 592                         data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
 593                 else
 594                         data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
 595                 if (data < 0)
 596                         return -EIO;
 597                 break;
 598         case V4L2_CID_GAIN:
 599                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 600                         return -EINVAL;
 601                 /* See Datasheet Table 7, Gain settings. */
 602                 if (ctrl->value <= qctrl->default_value) {
 603                         /* Pack it into 0..1 step 0.125, register values 0..8 */
 604                         unsigned long range = qctrl->default_value - qctrl->minimum;
 605                         data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
 606
 607                         dev_dbg(&client->dev, "Setting gain %d\n", data);
 608                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 609                         if (data < 0)
 610                                 return -EIO;
 611                 } else {
 612                         /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
 613                         /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
 614                         unsigned long range = qctrl->maximum - qctrl->default_value - 1;
 615                         /* calculated gain: map 65..127 to 9..1024 step 0.125 */
 616                         unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
 617                                                1015 + range / 2) / range + 9;
 618
 619                         if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
 620                                 data = gain;
 621                         else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
 622                                 data = ((gain - 32) * 16 + 16) / 32 + 80;
 623                         else
 624                                 /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
 625                                 data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
 626
 627                         dev_dbg(&client->dev, "Set gain from 0x%x to 0x%x\n",
 628                                 reg_read(client, MT9T031_GLOBAL_GAIN), data);
 629                         data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
 630                         if (data < 0)
 631                                 return -EIO;
 632                 }
 633
 634                 /* Success */
 635                 mt9t031->gain = ctrl->value;
 636                 break;
 637         case V4L2_CID_EXPOSURE:
 638                 /* mt9t031 has maximum == default */
 639                 if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
 640                         return -EINVAL;
 641                 else {
 642                         const unsigned long range = qctrl->maximum - qctrl->minimum;
 643                         const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
 644                                              range / 2) / range + 1;
 645                         u32 old;
 646
 647                         get_shutter(client, &old);
 648                         dev_dbg(&client->dev, "Set shutter from %u to %u\n",
 649                                 old, shutter);
 650                         if (set_shutter(client, shutter) < 0)
 651                                 return -EIO;
 652                         mt9t031->exposure = ctrl->value;
 653                         mt9t031->autoexposure = 0;
 654                 }
 655                 break;
 656         case V4L2_CID_EXPOSURE_AUTO:
 657                 if (ctrl->value) {
 658                         const u16 vblank = MT9T031_VERTICAL_BLANK;
 659                         const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
 660                         unsigned int total_h = mt9t031->rect.height +
 661                                 mt9t031->y_skip_top + vblank;
 662
 663                         if (set_shutter(client, total_h) < 0)
 664                                 return -EIO;
 665                         qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
 666                         mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
 667                                  (qctrl->maximum - qctrl->minimum)) /
 668                                 shutter_max + qctrl->minimum;
 669                         mt9t031->autoexposure = 1;
 670                 } else
 671                         mt9t031->autoexposure = 0;
 672                 break;
 673         }
 674         return 0;
 675 }
 676
 677 /* Interface active, can use i2c. If it fails, it can indeed mean, that
 678  * this wasn't our capture interface, so, we wait for the right one */
 679 static int mt9t031_video_probe(struct i2c_client *client)
 680 {
 681         struct soc_camera_device *icd = client->dev.platform_data;
 682         struct mt9t031 *mt9t031 = to_mt9t031(client);
 683         s32 data;
 684         int ret;
 685
 686         /* Enable the chip */
 687         data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
 688         dev_dbg(&client->dev, "write: %d\n", data);
 689
 690         /* Read out the chip version register */
 691         data = reg_read(client, MT9T031_CHIP_VERSION);
 692
 693         switch (data) {
 694         case 0x1621:
 695                 mt9t031->model = V4L2_IDENT_MT9T031;
 696                 icd->formats = mt9t031_colour_formats;
 697                 icd->num_formats = ARRAY_SIZE(mt9t031_colour_formats);
 698                 break;
 699         default:
 700                 dev_err(&client->dev,
 701                         "No MT9T031 chip detected, register read %x\n", data);
 702                 return -ENODEV;
 703         }
 704
 705         dev_info(&client->dev, "Detected a MT9T031 chip ID %x\n", data);
 706
 707         ret = mt9t031_idle(client);
 708         if (ret < 0)
 709                 dev_err(&client->dev, "Failed to initialise the camera\n");
 710
 711         /* mt9t031_idle() has reset the chip to default. */
 712         mt9t031->exposure = 255;
 713         mt9t031->gain = 64;
 714
 715         return ret;
 716 }
 717
 718 static int mt9t031_g_skip_top_lines(struct v4l2_subdev *sd, u32 *lines)
 719 {
 720         struct i2c_client *client = sd->priv;
 721         struct mt9t031 *mt9t031 = to_mt9t031(client);
 722
 723         *lines = mt9t031->y_skip_top;
 724
 725         return 0;
 726 }
 727
 728 static struct v4l2_subdev_core_ops mt9t031_subdev_core_ops = {
 729         .g_ctrl         = mt9t031_g_ctrl,
 730         .s_ctrl         = mt9t031_s_ctrl,
 731         .g_chip_ident   = mt9t031_g_chip_ident,
 732 #ifdef CONFIG_VIDEO_ADV_DEBUG
 733         .g_register     = mt9t031_g_register,
 734         .s_register     = mt9t031_s_register,
 735 #endif
 736 };
 737
 738 static struct v4l2_subdev_video_ops mt9t031_subdev_video_ops = {
 739         .s_stream       = mt9t031_s_stream,
 740         .s_fmt          = mt9t031_s_fmt,
 741         .g_fmt          = mt9t031_g_fmt,
 742         .try_fmt        = mt9t031_try_fmt,
 743         .s_crop         = mt9t031_s_crop,
 744         .g_crop         = mt9t031_g_crop,
 745         .cropcap        = mt9t031_cropcap,
 746 };
 747
 748 static struct v4l2_subdev_sensor_ops mt9t031_subdev_sensor_ops = {
 749         .g_skip_top_lines       = mt9t031_g_skip_top_lines,
 750 };
 751
 752 static struct v4l2_subdev_ops mt9t031_subdev_ops = {
 753         .core   = &mt9t031_subdev_core_ops,
 754         .video  = &mt9t031_subdev_video_ops,
 755         .sensor = &mt9t031_subdev_sensor_ops,
 756 };
 757
 758 static int mt9t031_probe(struct i2c_client *client,
 759                          const struct i2c_device_id *did)
 760 {
 761         struct mt9t031 *mt9t031;
 762         struct soc_camera_device *icd = client->dev.platform_data;
 763         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 764         struct soc_camera_link *icl;
 765         int ret;
 766
 767         if (!icd) {
 768                 dev_err(&client->dev, "MT9T031: missing soc-camera data!\n");
 769                 return -EINVAL;
 770         }
 771
 772         icl = to_soc_camera_link(icd);
 773         if (!icl) {
 774                 dev_err(&client->dev, "MT9T031 driver needs platform data\n");
 775                 return -EINVAL;
 776         }
 777
 778         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
 779                 dev_warn(&adapter->dev,
 780                          "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
 781                 return -EIO;
 782         }
 783
 784         mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
 785         if (!mt9t031)
 786                 return -ENOMEM;
 787
 788         v4l2_i2c_subdev_init(&mt9t031->subdev, client, &mt9t031_subdev_ops);
 789
 790         /* Second stage probe - when a capture adapter is there */
 791         icd->ops                = &mt9t031_ops;
 792
 793         mt9t031->y_skip_top     = 0;
 794         mt9t031->rect.left      = MT9T031_COLUMN_SKIP;
 795         mt9t031->rect.top       = MT9T031_ROW_SKIP;
 796         mt9t031->rect.width     = MT9T031_MAX_WIDTH;
 797         mt9t031->rect.height    = MT9T031_MAX_HEIGHT;
 798
 799         /* Simulated autoexposure. If enabled, we calculate shutter width
 800          * ourselves in the driver based on vertical blanking and frame width */
 801         mt9t031->autoexposure = 1;
 802
 803         mt9t031->xskip = 1;
 804         mt9t031->yskip = 1;
 805
 806         mt9t031_idle(client);
 807
 808         ret = mt9t031_video_probe(client);
 809
 810         mt9t031_disable(client);
 811
 812         if (ret) {
 813                 icd->ops = NULL;
 814                 i2c_set_clientdata(client, NULL);
 815                 kfree(mt9t031);
 816         }
 817
 818         return ret;
 819 }
 820
 821 static int mt9t031_remove(struct i2c_client *client)
 822 {
 823         struct mt9t031 *mt9t031 = to_mt9t031(client);
 824         struct soc_camera_device *icd = client->dev.platform_data;
 825
 826         icd->ops = NULL;
 827         i2c_set_clientdata(client, NULL);
 828         client->driver = NULL;
 829         kfree(mt9t031);
 830
 831         return 0;
 832 }
 833
 834 static const struct i2c_device_id mt9t031_id[] = {
 835         { "mt9t031", 0 },
 836         { }
 837 };
 838 MODULE_DEVICE_TABLE(i2c, mt9t031_id);
 839
 840 static struct i2c_driver mt9t031_i2c_driver = {
 841         .driver = {
 842                 .name = "mt9t031",
 843         },
 844         .probe          = mt9t031_probe,
 845         .remove         = mt9t031_remove,
 846         .id_table       = mt9t031_id,
 847 };
 848
 849 static int __init mt9t031_mod_init(void)
 850 {
 851         return i2c_add_driver(&mt9t031_i2c_driver);
 852 }
 853
 854 static void __exit mt9t031_mod_exit(void)
 855 {
 856         i2c_del_driver(&mt9t031_i2c_driver);
 857 }
 858
 859 module_init(mt9t031_mod_init);
 860 module_exit(mt9t031_mod_exit);
 861
 862 MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
 863 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
 864 MODULE_LICENSE("GPL v2");